docs: def dskgtl(keywrd):
      """
      Retrieve the value of a specified DSK tolerance or margin parameter.
      
      https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/dskgtl_c.html
      
      :param keywrd: Code specifying parameter to retrieve. 
      :type keywrd: int
      :return: Value of parameter.
      :rtype: float
      """
      keywrd = ctypes.c_int(keywrd)
      dpval  = ctypes.c_double(0)
      libspice.dskgtl_c(keywrd, ctypes.byref(dpval))
      return dpval.value